98 High

Boiler Fault Code 98

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 98 appears across 3 boiler brands and 9 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is having trouble communicating with an internal control board responsible for managing extra heating system features, which may prevent your heating or hot water from working correctly. (As reported on Navien NCM 1130HH)

Pick your boiler brand for the 98 fix

Alpha 98 7 models ECA 98 1 model Navien 98 1 model

Source

Information for the 98 fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026